


Cult Case

by WotanAnubis



Category: Brooklyn Nine-Nine (TV)
Genre: Alternate Universe - Urban Fantasy, Gen, Werewolf Rosa
Language: English
Status: Completed
Published: 2017-03-02
Updated: 2017-03-02
Packaged: 2018-09-27 21:57:51
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,003
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10053143
Author URL: https://archiveofourown.org/users/WotanAnubis/pseuds/WotanAnubis
Summary: In which Rosa helps Amy catch a glimpse of a slightly different world.





	

**Author's Note:**

> How is this the only idea for Brooklyn Nine-Nine fic I've had?

Amy Santiago was not walking towards the desk of Rosa Diaz. She just happened to be sort of ambling about, having little to do at the moment, and on her casual, non-specific stroll, she just sort of happened to get closer and closer to-

"What do you want, Amy?" Rosa said, not looking up from the giant stack of paper she was working on.

Amy eagerly took a seat. "OK, so, I've been looking over your last few cases recently," she began.

"Uh-huh," Rosa said, looking at her paper as though she hated it, which was probably the case.

"In the last two months alone, you took down three rogue vampires, broke up a vicious werewolf pack-"

"They weren't a pack, just a bunch of teens with out-of-control hormones."

"But they were still werewolves! And then you stopped that necromancer before he could summon more than about twelve zombies."

A smile flashed across Rosa's face. "That was a fun night. I could've stopped him earlier, but he could only send those zombies at me one at a time so it was good headshot practice."

"OK. And just a few days ago you took down the Cult of Xwb... of Brl... of Phre..."

"Just call him the Star Beast with Ten Millions Mouths," said Rosa. "It's easier."

"Does he really have ten million mouths?"

"I dunno," said Rosa replied. "But it's prophesied that on his return he's going to eat all dreams and leave only nightmares, so I'm not exactly eager to find out."

"Oh. Anyway, that doesn't matter. The point is, you get all the supernatural cases."

"Yup," said Rosa.

"So what's your secret? Why do you get all the magical assignments?"

"It's no secret," said Rosa. "I'm a werewolf."

"You're a _werewolf_?"

_Now_ Rosa looked at her. It was only a brief glance, but it said a whole lot.

"I mean, of course you're a werewolf," said Amy. "Why wouldn't you be a werewolf? It makes total sense you're a werewolf."

Rosa rolled her eyes and turned her attention back to the mountain of paper.

"So what're you working on right now?" Amy asked.

"Still the cult case," said Rosa. "I stopped the summoning, but the leader got away. I know what he looks like, but other than that I got no name, no address, nothing. None of the rest of the cultists know each other outside the cult, so they're useless. Hoping to find something in this witness statement."

Amy glanced at the truly impressive heap of paper.

"How many witnesses?" she asked.

"Just the one. Fey. Can't keep their attention on one thing for ten seconds. Every time she almost says something useful she veers off into some tangent about a unicorn frolicking in a meadow or the beautiful emerald eyes of some past lover or she recites this haiku about Spring or tells me everything about this conversation she had with a dryad two hundred years ago and it just goes on and on and on and never gets anywhere."

"Sounds frustrating," said Amy sympathetically.

"Don't I know it. Used to be you could press a cold iron bar against their foreheads and that'd make 'em pay attention, but nowadays that's 'police brutality'."

"Well, do you know what you need?" Amy said, finally veering towards the point she'd wanted to make since the start. "You need a partner on this case."

Rosa looked at her. "No," she said.

* * * * *

"You need a partner on this case," said Captain Holt.

Amy and Rosa stood in front of Holt's desk. Amy wasn't actually bouncing with glee, but she gave the impression she might at any moment. The floor was practically vibrating with suppressed bounciness. Rosa stood silently, her habitual expression of annoyed disdain more disdainful than usual and a lot more annoyed.

"I really don't," said Rosa. "I've got everything practically wrapped up."

"And that is why I think it would be useful to assign Detective Santiago to you," said Captain Holt. "She has argued, and I agree, that you are currently the only one with any experience in supernatural cases and it would be in all our best interests if others were to gain some familiarity with the field as well. Consider it a training exercise."

"Unnecessary," said Rosa. "I can handle everything by myself."

"Well, you might get sick," said Amy.

"I'm a werewolf."

"You might take off for a month to go running in the wilderness, cut off from all human contact."

Rosa glared at her. "Good point. Fine. She can tag along."

Amy bounced.

"Whatever," Rosa continued. "But Captain, if she's coming with me, I'll need some money to buy her some jewelry."

"Of course," said Captain Holt. "That goes without saying."

* * * * *

The jewelry store was not what Amy had expected. It was small, cramped, dark and seemed to resent the presence of anything as intrusive as customers. Dusty display cases didn't so much show the glittering jewelry as begrudgingly allowing people to look at it. The only other person present was a gnarled, hunched-over little man at the cash register.

"So is this a dwarf store?" Amy asked in a hushed whisper.

"What are you talking about?" said Rosa.

"Well, is this a store run by dwarfs?"

"Of course not," said Rosa. "Why would you think that?"

"That man behind the counter is obviously a dwarf."

"He's human."

"Oh."

"But, in fairness, most of this stuff is forged by dwarfs."

"Ah- _ha_! I knew it."

"Most all jewelry is forged by dwarfs."

"Oh."

The two reached the counter. The gnarled little man looked up and smiled a very crooked smile.

"Detective Diaz. Always a pleasure," he said, sounding like he meant it.

"Mr. Hopkins. Need an iron necklace."

"I expected you might. Just iron? Or would you like some... additional protection?"

"Lemme check," said Rosa. "Hey, Amy?"

"Yes?"

"Have you embraced Jesus Christ as your Lord and Savior and accepted Him into your heart?"

"What?" said Amy.

"Well, do you intend to die in glorious battle so you may counted among the worthy dead in Valhalla?"

"Where did that come from?" Amy asked.

"OK, then. Would you eagerly sacrifice your own life so the Gods may be strengthened by your gift and the Sun will continue to burn?"

"That's just creepy," said Amy.

Rosa turned back to the cashier. "Just the iron necklace will do."

"As you say. It'll take but a moment."

Five minutes later, Amy gratefully stepped outside, happy to be back in the fresh New York air. Rosa followed, her expression not betraying much of anything.

"Here," Rosa said.

Amy took the offered necklace. It was... indeed a necklace. And it was sure made of iron. That was pretty much everything that could be said about it. Without getting unkind, in any case.

"Wear that under your clothes," said Rosa. "Make sure the iron's touching your skin."

Amy obediently put on the necklace. The iron was cold and uncomfortable.

"So why did you get this for me?" she asked.

"I didn't feel like wading through the fey's statement with you, so we're following up on my other lead," Rosa said. "And he's terribly dangerous."

"Are you going to call for backup?" Amy asked. "If this guy's so dangerous, I mean."

"Is the necklace touching your skin?" Rosa asked.

"Yes."

"Then no."

* * * * *

"I should probably fill you in a bit on the guy we're meeting," said Rosa.

The pair walked up a large, airy, if slightly decaying staircase in an apartment building that was itself large, airy and slightly decaying. It stood on the very edge of one of the more magical neighborhoods. Here, in the quiet air, if one were to listen very carefully, they might hear the laughter of sylphs.

"He's a manager of sorts at Star & Moon Community Center," Rosa continued, ignoring the elementals playing with her hair. "It's where Dr'gh't's'tr's Cult met."

"They met at a Community Center?" Amy asked. "Get off," she added, swatting at a sylph that was pulling at her hair. The barely-visible elemental giggled and glided away.

"What were you expecting? A big old dungeon underneath an ancient manor or something? These guys weren't exactly loaded."

"Yeah, but, a Community Center. Since they'd been planning to destroy the world they could've at least met in a graveyard or something," said Amy while a sylph floated through her hair and gave her a windswept look.

"I'll be sure to add their lack of style to the list of charges," said Rosa. "Anyway, the important thing for you, right now, is to not say anything. Do not answer any questions. _Especially_ not if they're directed at you. Let me do **all** the talking. Got that?"

"Sure," said Amy.

"This is _important_ , Santiago," Rosa snapped. "Keep. Quiet."

Amy blinked. "I got it. No problem."

"Good."

Rosa knocked on the door. The sylphs fled.

After a moment or two the door opened, revealing a slight, beautiful figure. His features were delicate and refined, his beautiful hair flowed down onto his back. His dark eyes shone with the stars in its depths. His clothes were nothing much to write home about, but they fitted his slender, elegant frame perfectly and only enhanced his sense of divine perfection.

"Detective Rosa Diaz," the elf said. Every word was its own, self-contained symphony so beautiful it would make angels weep.

And yet... And yet...

There was something about the elf Amy couldn't quite catch. A hunger, perhaps. A yearning for... something.

"Peachblossom," Rosa said with a curt nod.

"I see you are not alone for once," the elf named Peachblossom said with a delighted smile. "And who might this kind lady be?"

"This is Detective Cortez," Rosa said before Amy could open her mouth.

The elf bowed formally. "I am positively delighted to meet you," he announced.

"We're not here to chat," said Rosa. "What do you know of the Cult of Dr'gh't's'tr? They met in the Star & Moon."

"They were wonderful guests," said the elf. "They met every Wednesday night and when they left, they always carefully stacked the chairs and cleaned up the mystic circles. Not every group is so considerate."

"Good for them. You know the name of their leader?"

"Oh come now," said Peachblossom. "Surely you do not expect me to betray client confidentiality?"

"I'll let you sing to Detective Cortez here."

"Deal," the elf said instantly.

"The name," said Rosa.

"I'll tell you what I know. After," said the elf. "Song first, information second. Humans renege on their deals so easily."

Rosa shrugged indifferently. "Fine. Get it over with."

The elf smiled at Amy and sang. His normal speaking voice was a melody by itself, but his song was something else entirely. It was flowers blooming in Spring. It was the sun shining through forest leaves. It was all cute animals playfully chasing each other. It was a warm and calming song and its warmth wrapped itself around Amy.

And bounced off.

It was a beautiful song, but it was full of disharmonious screeching. It was a field of thorns and brambles. It was a dead forest under a sunless sky. It was a predator tearing out the throat of innocent prey.

The iron necklace burned on Amy's skin.

The last wonderful, awful note died away and the elf smiled beautifully.

"You done?" said Rosa. "Name. Now."

The elf looked briefly annoyed, but soon enough he looked happy and delighted once more.

"The man you're looking for called himself John Smith," said Peachblossom. "I sincerely doubt it's his real name. But he works at a flower shop nearby. The Green Thumb. You'll find him there."

"Great," said Rosa. "Let's go."

"Oh, but please," said the elf. "Kind Detective Cortez. Will you not stay with me a while longer? Shall we not sing together?"

Rosa didn't answer. The silence dragged on, thick and heavy, and the elf's perfect countenance became marred with a frown.

"Oh, uhm..." Amy began. Since Rosa made no move to stop her she continued. "I'm afraid we must be going. We've still got this case to solve on, after all."

" _What!?_ " the elf screeched, outraged.

"She's wearing iron, you idiot," said Rosa. "You really think I'd let you sing to someone unprotected? Come on."

"You lied to me!" the elf raged. "You broke our deal!"

"No. I said you could sing to her and you sang to her. That's all."

"Get out!" the elf hissed. "Get out and bother me no more!"

The door slammed shut. Rosa shook her head, smiling vaguely.

"Elves. So temperamental."

"What just happened there?" Amy asked, while a sylph floated back and whispered through a strand of her hair.

"He thought I'd let him enthrall you and make you his plaything," said Rosa. "I think he was upset it didn't work."

"What? Why would he ever think you'd let him do that?"

"Because he's an elf," said Rosa. "Other people mean nothing them. And they all think other people mean nothing to anyone else either. He honestly thought I'd be perfectly willing to offer you up to get what I wanted."

"That's insane," said Amy.

"Perfectly normal for an elf," said Rosa. "C'mon, let's get going."

The two descended the stairs again in silence. More or less. They were silent. The sylphs dancing around them were laughing.

"So what do you think he'd have me do?" Amy asked, about halfway down.

"What?"

"The elf. Peachblossom. What would he have wanted with me, do you think?"

Rosa shrugged. "Probably the usual. Singing. Dancing. Making flower crowns."

"Oh," said Amy. "That doesn't sound so bad compared to-"

"And he'd have you doing it until you keeled over from exhaustion and died."

"Oh, that's bad."

"Yep."

"Also, would you mind telling me why you told that elf my name's Cortez?" Amy asked.

Rosa stopped and looked at her. "Seriously? You really need me to spell that out for you?"

"Consider it part of the training?" Amy suggested.

Rosa grunted. "You never, ever give an elf your true name. _Ever_."

"But he called you Rosa Diaz," said Amy.

"So?" said Rosa.

There was another moment of almost-silence. Then Amy spoke again.

"That statement from the fey you were struggling with," she began.

"What about it?" Rosa asked.

"Well, she talked about a meadow with, I assume, green grass. She talked about green eyes. And dryads are green, aren't they?"

"They're basically trees, so yeah."

"And Spring is famous for making the flowers bloom," Amy continued. "Now it turns out our suspect is working at a flower shop called The Green Thumb."

Rosa stopped abruptly. "Goddamn fey," she growled.

* * * * *

The Green Thumb was depressingly normal. It looked very much like a well-run flower shop because that's what it was. Amy felt vaguely offended. The sinister lair of an evil cult leader shouldn't look so floral and festive.

The suspect, 'John Smith', worked the cash register. Rosa had identified him from the other side of the street and sent Amy in alone. It made sense. Rosa knew what he looked like, it was possible he knew what she looked like. But he didn't know Amy, so he probably wouldn't bolt if he saw her.

Even so, who knew what strange, blasphemous power a follower of the Frht... of Lhkj... of the Star Beast with Ten Million Mouths might have. Suddenly the iron necklace didn't feel like much protection. Her gun was certainly worthless.

Amy reached the cash register. The man behind it was offensively ordinary. Black hair, brown eyes, five o' clock shadow. He wasn't handsome, he wasn't ugly. He was just some guy. His eyes weren't bloodshot, his grin wasn't cracked and crazed. There were no tentacles hiding under his hairline. He didn't even have any tattoos. How dare he?

He smiled at her. "Can I help you?"

Amy showed him her badge. "NYPD. You're under arrest for conspiracy to end the world."

The man raised his hands. "I surrender."

"What, just like that?" said Amy.

"Well, you've got a gun, don't you?" he replied. "I'm not crazy."

* * * * *

"This has been the most disappointing arrest ever," said Amy.

"Yeah, he gave up without a fight," said Rosa. "What a shame."

"Are you being sarcastic?" Amy asked.

"Maybe."

The police car made its way back to the precinct very slowly. The suspect, whose name had turned out to be Mark, sat handcuffed on the back seat.

"I just... I finally get assigned to a magical case and it turns out we just needed to pick up some guy."

"Told you I had it almost wrapped up," said Rosa.

"He didn't even try to run away," Amy groused. "I didn't even get to see you turn into a wolf and chase him."

"Turn into a wolf?" said the suspect. "She's a werewolf? I'm in a car with a _werewolf_?"

"Shut up, you!" Amy and Rosa chorused.

"Don't let her eat me!" Mark shrieked.

"Be. **Quiet!** " Rosa snarled.

"Yes ma'am," the suspect whimpered.

"How did you ever wind up leading a cult," Rosa said.

"Found this old book in my gran's house," said the suspect. "Thought it looked cool."

"Of course you did," said Rosa.

"Still, that's case closed," Amy said. "Smooth and easy. I think the Captain will see this as a success, don't you?"

"Probably," said Rosa.

"So he'll probably let us partner up on other supernatural cases, right?"

Rosa sighed. "I wouldn't be surprised if he did."

"Great," said Amy. "I'm gonna learn all about your world."

"What do you mean 'my world'?" Rosa said.

"I'm going to be an expert before the month's out," Amy continued happily. "You'll see. And hey, maybe next time I'll also see you turn into a wolf."

"You really want to see me transform, don't you?"

"I really do," Amy said.

Rosa chuckled to herself. "You know, it's full moon next Saturday. I could transform and chase someone then."

"Really?" said Amy, smiling. "Who'll you be chasing? Wait, me. You'll be chasing me, won't you?"

Rosa grinned. "You up for it?"


End file.
